1) Field of the Invention
The present invention relates to a wiring device and wiring method suitable for designing LSIs (Large Scale Integrated Circuits) or printed boards.
2) Description of the Related Art
Recently, it has been required to assemble and arrange densely components on semiconductor large scale integrated circuits (LSIs), multichip modules (MCMs), printed boards and the like and then to wire the components with a small number of signal layers in short time. Generally, various circuits above described are designed using CAD (Computer Aided Design).
For example, in order to deal with various wiring problems in printed wiring boards each with plural part pins, a CAD device edits wiring patterns and then decides a wiring rule on wiring boards.
Various circuits have been required to form in higher density and higher performance. The circuit characteristics are largely affected by crosstalk noise occurred due to plural lines forming wiring patterns which are closely arranged.
Hence in order to edit wiring patterns for semiconductor LSIs, multichip modules (MCM), printed wiring boards or the like using the CAD device, it is necessary to design circuits with circuit characteristics immune to noise components by taking account of the crosstalk noise.
In general CAD devices, a wiring pattern editing system that edits wiring patterns as well as a transmission path analytic simulator that analyzes a crosstalk noise occurring when a circuit including wiring patterns edited by the wiring pattern editing system is in an active state are arranged independently and cannot perform their jobs concurrently.
That is, when an operator edits a wiring pattern using the wiring pattern editing system, the wiring pattern editing system is closed once. Then crosstalk noise occurring when a circuit is operated by activating the transmission path analytic simulator are analyzed.
When it is found that the crosstalk noise affect significantly the circuit characteristics, the above-mentioned transmission path analytic simulator is closed. Then the wiring pattern editing system is reactivated to specify and correct a spot causing crosstalk noise on a wiring pattern.
In concrete, when an operator corrects an edited wiring pattern, by considering the crosstalk noise, the analytical solution of the transmission path analytic simulator, for example, is printed. The spot causing crosstalk noise on the wiring pattern is specified and corrected by contracting the wiring pattern displayed on the screen of the wiring pattern editing system reactivated with the analytical solution by the operator himself.
In the CAD system, since the wiring pattern editing system and the transmission path analytic simulator are independently arranged, they cannot be activated at the same time. Hence there is the problem of needing much effort to correct the wiring pattern while referring to the solution from the transmission path analytic simulator.
Particularly, when the analytical solution of the transmission path analytic simulator is displayed as a graph showing a crosstalk noise on an edited wiring pattern, it is impossible to specify the crosstalk noise causing spot on the wiring pattern by referring to only the graph. Hence, in some cases, the noise causing spot cannot be specified principally even when the graph is contrasted with the wiring pattern displayed on the screen of the wiring pattern editing system reactivated.
In that case, the noise causing spot must be specified and corrected by presuming a noise causing spot using the analytical solution of the transmission path analytic simulator and repeating the noise causing spot presumed on the wiring pattern in the wiring pattern editing system. This procedure forces the operator to do too much work.
On the other hand, the system that can deal with various wiring problems and can edit automatically wiring patterns is under development as a wiring pattern editing system.
However, even when such an automatic wiring pattern editing system is adopted to the above-mentioned CAD system, the wiring pattern must be manually corrected based on the analytical solution of the transmission path analytic simulator.
Hence, there is the problem of being hindered from improving the automatic wiring application rate.